1. Field of the Invention
The present invention is directed to a wide field-of-view (FOV) simulator heads-up display (HUD) and, more particularly, to a low-cost system having a selective holographic reflector combiner with a low-cost relay optical system.
2. Description of Related Art
Holographic information display systems for use in aircraft wherein an image of information can be projected onto a combining glass in the pilot's FOV to permit viewing the information, while continuing to view the outside scene through an aircraft canopy, have been well known. The information to be presented by the HUD includes instrument panel information, flight symbology, sensor video, etc. It has thus become quite common in high performance aircraft to utilize a combiner within the pilot's FOV to permit the pilot to continue viewing the terrain or outside scenery while monitoring the necessary information being generated by the aircraft.
In view of the high cost of operating such aircraft and the requirements for the pilots to have high proficiency, there has developed a need to use simulators for the training of pilots. These simulators seek to emulate the environment of the cockpit and include the HUDs that the pilot will experience in actual flight. Usually a simulator will adopt the same HUD that has been designed for high performance aircraft, and attempts will be made to modify this HUD design to accommodate the simulator environment. Thus the optics can be somewhat modified and a cathode ray tube (CRT) image source can be repositioned. Usually to reduce any retooling costs and design costs, the basic structure of the aircraft HUD and its optical and mechanical design philosophy will generally be carried forward in the simulator environment.
Examples of HUDs can be found in U.S. Pat. No. 3,915,548, U.S. Pat. No. 3,940,204, and U.S. Pat. No. 3,549,803.
The prior art is still seeking to provide a low-cost simulator HUD that can simulate the high performance of an aircraft HUD while maintaining the focus of the imagery near or on the surface of the scenery as represented by a dome or very close rear projection screen.